Accordion pickup



Dec. 5, 1961 Filed April 8, 1960 FIG. 1

2 Sheets-Sheet 1 /2 M 3 M /2 /7 27 Z M zzvmvron CZ/NTo/v A. MON/ 7547,

Dec. 5, 1961 c. A. MONFELT 3,011,381

ACCORDION PICKUP Filed April 8, 1960 2 Sheets-Sheet 2 LNVENTUR. CZ/A/7ZWV 14. /%Q2NQZEZJC United States Patent .Ofiice 3,011,381 ACCORDION PICKUP Clinton A. Monfelt, 1738 Marion, Denver, Colo. Filed Apr. 8, 1960, Ser. No. 20,872 2 Claims. c1. 84-676) This invention relates to electrical pickup apparatus for musical instruments, and more particularly to an improved microphone pickup arrangement for accordions.

A main object of the invention is to provide a novel and improved microphone pickup arrangement for accordions, the arrangement involving only a few parts, providing accurate sensitivity both to the high and low tones of the accordion, and being relatively easy to install in a conventional accordion without any substantial modification of the structure of the accordion.

A further object of the invention is to provide an improved accordion pickup arrangement which requires relatively inexpensive components, which is very compact in size so that it can be easilyv installed inside a conventional accordion without requiring any additional housings or other new structure, and being sufficiently compact in size so that it does not interfere with the operation of the accordion.

A still further object of the invention is to provide an improved accordion pickup arrangement which provides proper balance of tone and volume, which minimizes distortion, and which accurately responds to the entire tonal range of the instrument in which it is installed, being particularly eflicient in responding to and transmitting the tones in the upper portion of the tonal register of the instrument.

A still further object of the invention is to provide an improved pickup assembly for use in an accordion, the assembly involving only a few parts, being easy to install and requiring only a small amount of time for the installation thereof, and being so located that the control elements thereof are readily accessible and may be easily operated without interfering with the normal playing of the accordion.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a top view of an accordion provided with an improved pickup assembly in accordance with the present invention.

FIGURE 2 is an enlarged fragmentary vertical cross sectional view taken substantially on the line 2-2 of FIGURE 1 and showing the manner in which the pickup microphone is mounted adjacent the ends of two of the treble reed blocks of the accordion.

FIGURE 3 is a cross sectional view taken substantially on the line 33 of FIGURE 2.

FIGURE 4 is a schematic wiring diagram showing the electrical connections of the pickup microphone, control device, and output jack of the pickup assembly employed in FIGURES 1 to 3, and illustrating the manner in which the assembly is connected to a reproducing system.

FIGURE 5 is a pictorial wiring diagram of the circuit shown in FIGURE 4.

Referring to the drawings, 11 designates an accordion of substantially conventional construction and having a treble side 12 and a base side 13 with a bellows 14 connecting said sides. The treble side 12 includes a piano keyboard 15 and the base side 13 is provided with the usual push button keyboard 16. The treble side of the accordion is provided with the rigid wall 17 located ad jacent the keyboard 15. Also provided in the treble side of the accordion are the accordion reed blocks 18 which support the reeds and which are affected by air passing thereby, in the usual manner of operation of an accordion.

3,011,381 Patented Dec. 5, 1961 In accordance with the present invention a bracket member 20 is secured to an adjacent pair of treble reed blocks 18, 18, and a crystal microphone 19 is suitably mounted in the bracket member and is thus supported in the space between the pair of reed blocks 18, 18. As shown in FIGURES 2 and 3, the crystal microphone 19 faces the base side of the accordion and is enclosed in the bellows 14. Suitable cushioning means 21, such as sponge rubber, or the like, is provided between the crystal microphone 19 and the spaced supporting arms 24 of the bracket member so as to cushion the microphone with respect to the relatively rigid bracket member 20.

As previously mentioned, the bracket member 20 is provided with the supporting arms 24 which are spaced at degrees with respect to each other to define a receiving socket for the microphone 19, the arms 24 being inturned at their ends to define retaining lugs, and the cushioning strips 21 being disposed between said retaining lugs and the microphone 19 in the manner shown in FIGURES 2 and 3. The microphone 19 is thus resiliently supported in the space between the pair of adjacent reed blocks 18, 18 and is thus supported in a position to accurately respond to sound vibrations generated in this space, and particularly, the vibrations developed in the base side of the accordion, since the microphone faces said base side. However, since the microphone is substantially omni-directional, it also responds accurately to the treble tones generated by the reeds of the treble reed blocks, located relatively closely adjacent thereto.

Designated generally at 25 is a control unit which is mounted on the rigid wall 17 adjacent one end of the piano keyboard 15, and also mounted in the rigid wall 17 is an output jack 26 of the miniature type adapted to receive a conventional miniature plug 27. Thus, the plug 27 is connected by a suitable shielded cable 28 to the input of a conventional amplifier 29, and the output of the amplifier is connected to a loud speaker 30.

Control unit 25 comprises a volume control potentiometer 31, a tone control potentiometer 32, a bypass condenser 33, and a coupling resistor 34. The casings of the potentiometers 31 and 32 are rigidly connected to the spaced arms 35 and 36 of a sleeved mounting lug 37 which is secured to and rigidly connects the potentiometers 32 and 31 in side-by-side relationship, as shown in FIGURE 5. The shielded output cable 38 extends through the sleeve portion 39 of the mounting lug 37, the center conductor of the cable 38 being connected to the central resilient contact arm 40 of the jack 26, and the shield of the cable being connected to the ring element 41 of the jack. Thus, the shield of the cable may be considered as ground in the circuit arrangement illustrated. A shielded cable 43 connects the microphone to the input of the control unit 25, the shield of the cable 43 being grounded, as shown in FIGURE 4, and the central conductor of said cable being connected to one terminal 46 of the volume control potentiometer 31, the opposite terminal of the potentiometer winding being grounded, as shown at 47. The adjustable contact element 48 of potentiometer 31 is connected through the coupling resistor 34 to the adjustable contact element 49 of the tone control potentiometer 32. One terminal 50 of the tone control potentiometer 32 is connected to ground through the bypass condenser 33. As shown in FIGURES 4 and 5, the resilient center contact arm 40 of the output jack 26 is connected to the adjustable contact element 49 of the tone control potentiometer 32 by a Wire 51.

As will be readily apparent from FIGURES 4 and 5, the sound vibrations are picked up by the crystal microphone 19 and are converted into electrical signals which are thus delivered to the winding of the potentiometer 31 which thus acts as a termination for the microphone cirwinding of the potentiometer 31 through the adjustable contact 48 and the coupling resistance 34 to the terminal wire 51, and thus to the resilient center contact arm 40 of output jack 26. A certain amount of high frequency signal energy is bypassed to ground through the tone control branch comprising a selected portion of the winding of the tone control potentiometer 32 and bypass condenser 33. The remaining signal energy is. delivered to the input of amplifier 29 and reproduced by the loud speaker 30. The potentiometers 31 and 32 are provided with the control knobs 53 and 54 which are located adjacent one end of the piano keyboard 15, as is clearly shown in FIGURES 1 and 3, allowing said knobs to be easily operated by the player of the accordion so that he may establish a desired balance between volume and tone at any time during the operation of the instrument.

In a typical embodiment of the invention, the coupling resistance had a value of 22,000 ohms, the potentiometers 31 and 32 each had a value of 500,000 ohms, and the bypass condenser 33 had a value of .01 microfarad.

As shown in FIGURE 3, the microphone cable extends through a bore 60 formed in one of the reed blocks 18, and thence to the control unit 25. The bore 60 is filled with wax, as shown at 61, around the microphone cable 43 to thus rigidly secure the cable in the reed block 18 and to prevent any undesired vibrations of the cable during the operation of the instrument.

The crystal microphone 19 is of conventional construction and is preferably of the miniature type. In a typical installation, the crystal microphone had a diameter of approximately one and one-quarter inches and a thickness of approximately of an inch. The frequency response of the microphone was substantially flat between a lower limit of thirty cycles per second to approximately 10,000 cycles per second as an upper limitwith an output of reasonable amplitude. Thus, the microphone was entirely adequate in picking up and transducing musical sounds over the entire tonal register of the instrument and developed substantial signal energy so that the loss introduced by the tone control circuit did not seriously interfere with the tone quality delivered by the loud speaker 30.

As will be Well understood, by employing miniaturized elements, such as a miniature output jack 26, and miniaturized potentiometers 31 and 32, as well as other miniaturized components, now commerciallyavailable, the assembly is easily installed in a standard accordion Without requiring any substantial modification of the accordion and without interfering with the normal playing thereof.

While a specific embodiment of an improved microphone pickup arrangement for an accordion has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In combination with an accordion having a treble side provided with a piano keyboard and having a rigid wall adjacent said piano keyboard and a baseside with a bellows connecting said sides and spaced treble reed blocks facing said base side and said bellows, bracket means secured to a pair of adjacent treble reed blocks, a microphone mounted in said bracket means and extending across said adjacent pair of reed blocks and facing said base side and being enclosed in said bellows, a control unit mounted on said rigid wall adjacent one end of said piano keyboard, an output jack mounted in said rigid wall adjacent said control unit, said control unit including a volume control potentiometer'and a tone control potentiometer, and conductor means contained within the accordion and connecting said microphone to said output jack through said control unit.-

2. In combination with an accordion having a treble side provided with a piano keyboard and having a rigid wall adjacent said piano keyboard and a base side with a bellows connecting said sides and spaced treble reed blocks facing said base side and said bellows, bracket means secured to a pair of adjacent treble reed blocks, a microphone mounted in said bracket means and extending across said pair of adjacent treble reed blocks and facing said base side and being enclosed in said bellows, a control unit mounted on said rigid wall adjacent one end of said piano keyboard, an output jack mounted in said rigid wall adjacent said control unit, said control unit including a volume control potentiometer connected across the microphone, a tone control potentiometer, a

condenser, and means connecting said tone control potentiometer and condenser in series across the output terminals of the volume control potentiometer, and conductor means contained within the accordion and connecting the output of said control unit to said output jack,

References Cited in the file of this patent UNITED STATES PATENTS 

